Client Controlled Nullability: Nullable Designator

[twof]

Spec changes
To get a better idea of where we stand, I'll add a poll so people can vote on their favorite option. This vote is non-binding, and is only one factor in choosing which syntax we land on I'll open new threads for people to discuss each option below.

In this thread we'll be discussing the behaviour of possible syntax that would act as the inverse of !. So far in other discussions, ? has been used, so ? will continue to be used in the presented options.

Syntax exists to turn Non-Nullable fields Nullable

Syntax does not exist to turn Non-Nullable fields Nullable

[twof]

Option 1

Syntax exists to turn Non-Nullable fields Nullable

Fields marked with this syntax are treated exactly like Nullable schema fields. If null is found for one of those fields, then it is returned and no related errors are added to the errors array

Example

Schema

type Business {
  name: String
  isStarred: Boolean!
}

Query

{
    business {
        name
        isStarred?
    }
}

If isStarred has a ? but resolves to null the result will be:

{
  "data": {
    "business": {
      "name": "Jamie",
      "isStarred": null
    }
  }
}

In addition to a means to selectively allow nulls to be resolved for Non-Nullable fields, this syntax was initially proposed as a boundary to the null propagation caused by Non-Nullable fields, or fields marked with ! as in Null Propagation Option 1.

Alternative syntax has also been proposed, but we can discuss that once we've decided that this is behaviour that we want in GraphQL, and should be included in the Client Controlled Nullability RFC.

[twof]

Initial proposal: graphql/graphql-spec#867 (comment)

[twof]

Option 2

Syntax does not exist to turn Non-Nullable fields Nullable

There is no way to turn Non-Nullable fields Nullable. This is the status quo.